<script type="text/javascript">
$(function() {
	$('#busca').blur(function() {
		if (!this.value) {
			$(this).val('Busque aqui');
		}
	});
	$('#busca').focus(function() {
		if (this.value == 'Busque aqui') {
			$(this).val('');
		}
	});
});
</script>
<form id="formBusca" action="<?php echo $this->baseUrl('busca');?>" method="get">
	<div class="busca">
		<input autocomplete="off" id="busca" name="busca" type="text" value="<?php echo (!empty($this->busca)) ? $this->busca: 'Busque aqui';?>" />
		<input type="submit" class="btnBuscar" value="" />
	</div>
</form>